A projector projecting and displaying a color image includes an illumination optical system, a color-light-separating optical system, liquid-crystal panels for corresponding kinds of separated color light, a color-light-synthesizing optical system, and a projection optical system. Light emitted from the illumination optical system is separated into three kinds of red, green, and blue light by the color-light-separating optical system, and the three kinds of color light are modulated by corresponding liquid crystal panels so as to generate corresponding images. Then, these images are synthesized by the color-light-synthesizing optical system and are projected by the projection optical system. The projection optical system focuses the three kinds of synthesized color light on a projection screen so as to project a color image onto the projection screen. Unfortunately, the projection optical system generally has chromatic aberration of magnification, thereby often causing a problem in that the sizes of projected image screens of the three kinds of color light are different from one another. In order to solve the above problem, a lens for compensating chromatic aberration of magnification can be included in a lens set forming the projection optical system; however this structure makes the projection optical system larger. As a countermeasure against this problem, a technique for compensating the above-mentioned chromatic aberration of magnification by providing a lens element or a prism element in a space from the emitting surface of each electrooptical device to the incident surface of the color-light-synthesizing optical system, more particularly, by providing a lens element or a prism element on the incident surface of a color-light-synthesizing prism without making the projection optical system larger has been known (for example, see Patent Document 1). Also, the color-light-synthesizing prism serving as the color-light-synthesizing optical system is sometimes formed so as to have a convex or concave dichroic surface (for example, see Patent Document 2).
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2000-206450 (Claim 1, FIG. 1)
Patent Document 2: Japanese Unexamined Patent Application Publication No. 11-38210.
Unfortunately, since the space from the emitting surface of each electrooptical device to the incident surface of the color-light-synthesizing prism is narrow, disposition of an additional lens element or prism element in the space makes the space narrower, thereby deteriorating the cooling feature of the electrooptical device. Also, it is often difficult to fabricate a lens element or a prism element in order to dispose it on the incident surface of the color-light-synthesizing prism, when the shape and the function of the color-light-synthesizing prism are taken into consideration.